What may have happened is when we tweek the perameters of the filter we sometimes notice issues. Lets say someone is avoiding the f word by writing fing we may add that, and later realize it is banning that in all combinations so we remove those filter peimeters.

We had this before with people spelling out bad words with spaces, and we banned that combo and every letter was starred in all words for a few hours. So its just a bit trial and error.